Investigation of dielectric relaxation in dipolar liquids from conductivity measurement

Conductivity (σijk’s) measurement method is proposed to investigate dielectric relaxation in ternary polar–nonpolar mixture of N,N-dimethyl formamide (DMF)(j) with pyridine(k) or acetonitrile(k) dissolved in p-xylene(i) at various weight fractions (wjk’s) and temperature under different bands (S, C, X and Ku) of microwave field applying Debye’s dielectric model. Ratio of slopes of imaginary σijk″ vs. wjk with real σijk′ vs. wjk of complex conductivity σijk* as well as linear slope of σijk″ vs. σijk′ are used to predict τjk’s (relaxation time) and µjk’s (dipole moments). Various molecular associations are also identified from the meaningful interactions among polar–nonpolar molecules in terms of τjk and µjk. Molecular dynamics or molecular environment surrounding the polar molecules DMF, pyridine or acetonitrile is extensively studied with the help of estimated thermodynamic energy parameters. The existence of Debye relaxation mechanism in polar–nonpolar mixture is authenticated by the estimated Debye factor. Microwave sensor development is also ascertained from various dielectric parameters like permittivity, conductivity and penetration depth under microwave field.